Utilization of cellulose liquors



Patented May 20, 1924.

UNITED STATES PATENT OFFICE.

ADDISON F. HOFFMAN, OF PITTSBURGH, PENNSYLVANIA.

UTILIZATION OF CELLULOSE LIQUORS.

No Drawing. 7

T a7] whom it may concern:

Be it known that I, ADDISON F. HOFFMAN,

citizen of the United states residing at Pittsburgh,.'in the county ofAllegheny and State of Pennsylvania, have invented new and usefulImprovements in the Utilization of Cellulose Liquors, of which thefollowing is a specification.

The manufacture of pulp from wood is ordinarily carried out in thiscountry, according to one of two principal processes, namely the sulfiteprocess or the soda process. In relatively few pulp mills otherdigestive fluids are used for the production of pulp. The extract orresidual liquid, obtained in the sulfite process, and commonly referredto in the art as sulfite cellulose waste liquor. consists of an aqueoussolution, strongly acid in reaction, containing salts of-calcium andmagnesium, and also containing lignone derivatives and also derivativesor compounds of resins, organic acids, starches, sugars, oils, tars,gums and perhaps other substances, the liquor in fact containingpractically all of the original constituents of the wood, except theeellulose, although of course in the form of compounds of a verydifierent nature than those contained in the ori inal wood treated. Theexact nature 0 this waste liquor also varies to some extent dependingupon the particular kind ,of wood under treatment, spruce wood giving aliquor having substantially different properties in many respects, fromthe liquor obtained from poplar and other pulp woods.

The liquor obtained in the soda pulp process is of a substantiallydifferent character, although it also contains compounds or derivativesof many of the substances enumerated above. This liquor is also alkalinein reaction.

According to the preferred form of the present invention, I separate thepulp as completely as possible from the liquor or this operationis-preferably effected by the pulp maker. I then add to the sufite wasteliquor, a suflicient amount of the soda pulp liquor to render themixture neutra or slightly alkaline. Both of these liquors may varyconsiderably in concentration or density, but with liquors of ordinaryc0n centration, say 8 to 10 Baum I find in some instances that one partof the soda liquor may be added to about three parts Application filedApril 1,

'ticular conditions of use.

1919. Serial No. 286,740.

of the sulfite waste liquor, with satisfactory results. It is notnecessary, although advisable that the liquors be used in such relativeproportions as to produce about the degree of alkalinity referred to inthis example. The neutral liquor seems to be more advantageous in manycases, since it is substantially more stable, thereby producmg lessdecomposition, both during the concentration operation, and while instorage after treatment. The neutralization produces a considerableamount of precipitate, which in many cases contains large quantities ofneutral calcium sulfite or magnesium sulfite, which may be utilized forthe preparation of bisulfite liquor, for paper or pulp making. Theprecipitate is preferably removed, for example by filtering or filterpressing, after which the remaining liquor is concentrated in suitableapparatus (vacuum apparatus being preferred) until a density of from 30to 35 Baum is obtained: The liquor may then again be filtered ifdesired, and is then ready to be run into receptacles for shipment. Thisconcentrated liquor is quite stable, can be kept for longperiods oftime, and is readily transportable, readily miscible with water andnon-inflammable.

This concentrated liquor has been found to give excellent results, whendiluted and used in place of oil, as a lubricant for the cutting edgesof tools used in metal cutting. The liquor in its concentrated form maybe diluted with say 8 to 10 parts of water at the time of use, but theseproportions can be varied widely, depending upon the par- The dilutedliquor is found to be suitable for use in drilling, turning, threadcutting, milling and various other operations in metal working. Theliquor may be supplied to the cutting edge or cutting point of the toolin any suitable manner, and for the best results should be suppliedfreely, that is to say in such quantities that the end of the tool, andthe work is kept thoroughly wet. As is the common practice in cuttingmetals, the liquor which drains away can be pumped up into the supplytank for reuse, as many times as desired.

The material has been found to be in some respects much superior to sodawater. soapy water, oil emulsions and similar liquids heretofore largelyemployed, and moreover seems to possess some point of advantage over thehighly expensive lard oil previously in common use.

While I prefer to employ the acid pulp liquor and soda pulp liquor, Ican use, although less advantageously, sulfite waste liquor neutralizedwith ordinary alkalies, for example soda, lime, magnesia, chalk, ormagnesite; In some instances soda pulp liquor, without neutralization,or after substantially complete neutralization, the same may beemployed. Neither of these two liquors seems to give as good results asthose obtained when using the acid pulp liquor and the alkaline pulpliquor.

In some instances, other kinds of pulp liquor, such as those producedfrom the sodium sulfate pulp process, or the sodium sulfide pulp processmay be used. but these are both inferior to the preferred forms of theinvention.

The concentrated liquor, or the concentrated and diluted liquor may beused alone, or may be used in conjunction with other cutting compounds,whether solutions or emulsions.

In a modified form of carrying out the process. the suh'it-e pulp liquorin a substantially neutral state, and the soda pulp liquor in itsoriginal alkaline state may he separately concentrated. and theconcentrated solutions mixed. This however is usually a more expensiveprocedure, and does not produce substantially better results, and inmany (:lSOS does not produce results which are even as good as thoseproduced in the preferred form of the process as above described, sincethere is more alteration in the colloidal content of the liquors, byevaporation in a strongly acid or strongly alkaline condition.

\Vhat I claim is:

1. The herein described process of lubricating cutting tools, whichcomprises supplying thereto a lubricant liquor containing sulfitecellulose waste liquor.

2. The herein described process of lubricating cutting tools, whichcomprises supplying thereto a lubricant liquid containing a concentrateof sulfite cellulose Waste liquor.

3. The herein described process of lubricating cutting tools, whichcomprises supplying thereto a lubricant liquor containing sulfitecellulose waste liquor rendered appreciably alkaline by the addition ofsoda pulp liquor.

4. A process of lubricating cutting tools which comprises supplyingthereto, sulfite waste liquor having an alkaline material added thereto.

5. The hereinabove described process of lubricating cutting tools, whichcomprises supplying thereto a lubricant liquor containing waste liquorof wood pulp manufacture, at least partially neutralized.

6. A process of lubricating cutting tools, which comprises supplyingthereto a lubricant liquor containing concentrated and re diluted wasteliquor of Wood pulp manufacture, at least partially neutralized.

7. A process of lubricating cutting tools, which comprises supplyingthereto a lubri cant liquor containing concentrated Waste liquor of woodpulp manufacture, at least partially neutralized.

In testimony whereof I affix my signature.

ADDISON F. HOFFMAN.

